Her cousin Christopher Hyatt (I3956) is credited as the founder of Hyattsville, Prince George's Co., MD (that is, not "Hyattstown," though I believe another of her ancestors must have been the founder of that town as well).

According to the Prince George's County Historical Society, "Hyattsville had its beginnings in the mid-nineteenth century, when C.C. Hyatt established his store and post office at the intersection of the Baltimore and Ohio Railroad and the turnpike. In the 1870s Hyatt platted a residential subdivision; the community prospered and grew, becoming an attractive and desirable place to live. Within a decade, it was a thriving commercial center." I don't know which Hyatt C.C. Hyatt is, but he is of a later generation than Jemima. [4, 5]